Automatic telephone system



July 31, 1934. M. MATHIAS AUTOMATIC T ELEPHONE SYSTEM Filed May 25,}932

g 3 a k M u v N.\% NNw xv 3 N w NSQ m NQ Patented July 31, 1934 1,968,087 AUTOMATIC TELEPHONE sYsTEM Maximilian Mathias,

Germany, assignor Aktiengesellschaft, Germany Berlin Charlottenburg, to Siemens & Halske Siemensstadt, near Berlin,

Application May 25, 1932, Serial No. 613,393

In Germany 6 Claims.

The invention relates to a circuit arrangement for automatic telephone systems having a plurality of exchanges in which Connections of various trafiic directions may be set up over the same group of junction lines.

A In known arrangements of this type theincoming end of the junction line is generally connected to a switching device of such a construction that, on the seizure of the line, it is connected to a switch or the like which'connects said line to the line group terminating in the contact row over which the junction line is seized at its outgoing end. This switching device is influenced by varying potentials being applied to the outgoing end of the line and accordingly connects the line to the appropriate line group.

This type of arrangements, however, are impaired by the defect that only a limited number of line groups can be selected at the incoming end of the junction line due to the fact that only a limited number of potential combinations is possible.

The present invention eliminates this defect by making it possible to select any number of line groups. This is accomplished by associating the connecting devices at the outgoing end of the junction line with switching means which function when definite 'traflic directions are selected and transmit over the junction line a frequency or a combination of frequenciescorresponding to the required direction which causes a switch at the incoming end'of the line to be set accordingly.

An embodiment of the invention'is shown in the drawing. An arrangement is illustrated by which connections from a sub exchange provided with the group selector GWl, the secondary lineswitch MW and the repeater Ue2 may be set up over-the junction line VL to a main exchange in which the group selector GW2 (in the form of a one-directional switch having a plurality of contact groups) is arranged, as well as connections within the sub-exchange completed over the group selector GWl and the repeater Uel. The switch wipersal, during the setting operation on the part of the group selector GW 1, is, raised, together with the other wipers of the-switch, to contact segmentsof which those brushed by the wiper during the setting-of connectionsto'the main exchange are connected to alternating current sources of supply from which emanate the various frequencies f1, f1+f2, f1+f2+f3.

In-principle the arrangement operates as follows: r

If a connection is to be set up from the sub-exchange to the main exchange, the secondary line- June 18, 1931 switch MW is set to the repeater Ue2 when the group selector GWl is seized. According to the level to which said group'selector GWl has been raised after its setting a definite frequency fl or combination of frequencies f1+f2 or f1+f2+f3 is transmitted over the junction line determined by the frequency in the group of junction lines corresponding to the contact groups I, II or III brushed by the switch wiper sa2.

The device operates in detail as follows: Relays A and C1 are energized and actuate their respective contacts when, for the purposeof completing a connection to the main exchange, the preceding connecting device seizes the group selector GWl in known manner. The closing of contact 801 causes the rotary magnet D3 of the sec ondary lineswitch MW to be intermittently energized and deenergized over earth, interrupter RUl, contacts 801, llq, 120, rotary magnet DS, battery, earth with the result that it continues to advance the secondary lineswitch until it has encountered an idle succeeding repeater Ue2. Relay Q is then energized over earth, contacts 1001, 130, relay Q contact 141', wiper 3 of the secondary lineswitch, c-lead, contacts 15 16h1, resistance, battery, earth. Relay Q opens its contacts llq and thereby cuts ofi the circuit for the rotary magnet DS, thus causing the secondary lineswitch to be brought to rest. It also closes its contacts 28:; and 3911.

When thegroup selector GWl now receives the impulses transmitted by the subscriber, relay A accordingly is intermittently energizedand deenergized. Contact 1a is re-closed on the first deenergization on the part of relay A and this causes relays V and E1 to be energized over earth, contact 701, relay-V,contact 1a, relay E1, battery, earth. Relay E1 closes its contact 17e1 with the result that, simultaneously with the release of relay A which caused contact 3a to be closed, thefollowing circuit for the vertical magnet H of the switch is completed: earth, contacts 71p, 3a, 17e1, 2010, magnet H, battery, earth. The vertical magnet is then actuated in accordance with the number of impulses received and raises the wipers a, b, 1 c and seal accordingly, at the same time closing the oil-normal contact 19k on the first vertical step. At the end of the impulse series the switch wiper sal, according to the number of impulses transmitted, is set to a contact segment to which the frequencies'fl, f1+f2, fl+f2+f3 are applied. The c-wiper of the group selector at this moment is set in front of the first contact of the level wherein the contacts are inter-connected according to the drawing. If the rotary magnet D1 is re-energized over earth, interrupter RUl, contacts 21101, 181;, 19k, magnet D1, battery, earth after the release of relay V and consequently the c-wiper is actuated, relays P1 and R are energized over earth, contact 22el, relay P1, cwiper, relay R, battery, earth when said c-wiper is set to the first of the interconnected contacts. Relay R then throws over its contacts 271- and 141' into positions 371' and 38r. The closing of contact 38r causes relay F to be energized over earth, contacts 1001, 130, relay Q, contacts 381", 39g, wiper 4, d-lead, relay F, battery, earth. Relay F throws over contact 29 into position 401 and thereby prepares the circuit for relay J1 for the transmission of the succeeding impulse series. Moreover, relay F closes contact 72 which connects up relay G thus causing relay H1 also to be re-energized over contact 73g.

lhe energization of relay R may now be retarded in such a manner that the contacts of the row to which the relay is connected are only interconnected from their second or one of the succeeding contacts. The circuit which extends over contact 277 then remains for a corresponding period with the result that the duration of the impulse transmitted over the junction line VL can be determined in this manner as indicated below.

A circuit over the current source of supply f1, switch wiper sal, contacts 261), 5a, 277', 2811, switch wiper 1, a-lead, contacts 29f, 3071, 32), b-lead, switch wiper 2, contact 331', earth, remains in operation until relay R has been energized due to the fact that the switch wiper sal at the end of the impulse series is set to, for example, the seg ment which is connected to the alternating current source of supply having the frequency f1. Consequently an impulse of the frequency 1 is transmitted to the group selector GW2 over the line VL.. This impulse influences relay J2 which closes its contact 417'2 and consequently connects up relay S over its winding I. Relay S, when en'- ergized, closes its contact 425 with the result that it is maintained energized and also causes relay C2 to be energized in the following circuit: earth, contact 43302, winding I of relay C2, contact 423, winding II of relay S, battery, earth. Relay C2 closes contact 46c2, thus causing the rotary'magnet of the switch GWZ to be intermittently energized in the following circuit: earth, interrupter RU2, contacts 4.7172, 46c2, magnet D2, battery, earth and consequently to advance its switch wipers until they find an idle outgoing line. Due to the contacts M02 and 488 also having been closed on the energization of relays C2 and S, the group selector GW2 hunts for an idle junction line in group I by the switch wiper sa2 being caused to brush this contact group in the following circuit: earth, contacts 4.402, @853, 4.91., 5011,, wiper sa2, relay P2, c-wiper of the group selector GWZ, outgoing c-lead. As soon as such a line is found relay P2 is energized and opens contact 47p2, thus cutting off the circuit for the magnet D2 with the result that the group selector is brought to rest. Relay P2, in addition, closes its contact 51p2 and thereby guards the group selector in known manner against further seizures, finally switching it through to the succeeding con.- necting device by means of contacts 52122 and 53192. Relay P2 also closes contact 54122 with the result that the succeeding impulse series, received by relay J2 and transmittedto relay J1 by the intermittent closing of contact 4a and from this relay further extended over the junction line VL by the actuation of contacts 6811 and 6971, may

7 impulse.

be transmitted over the outgoing a-lead to the succeeding connecting devices over contacts 70i2, Mp2, and 53122.

If, on the other hand, the group selector GWl has been raised to another level for the setting up of another connection from the sub-exchange to the main exchange, the switch wiper sal at the end of the impulse series transmitted to the switch is set, for example, to the segment to which the frequencies f1+f2 are connected. If the group selector has been set to the repeater Ue2, a further impulse now indicating the frequencies f1 and f2 is transmitted over the junction line VL the manner indicated above. Relays J2 and X in the group selector GW2 are energized by this Relay J2 again connects up relay S and this relay in turn relay 02 with the result that the circuit for the magnet D2 is closed over contact 4602 and the switch starts to operate. Due to the fact that contact 560: is now closed by the energization of relay X, relay T also is energized over: earth, contact 43p2,-winding I of relay C2, contact 563;, relay T, battery, earth, .Relay T remains energized over its contact 5% and, in addi-v tion, throws over its contact 49; into position 582i. The switch wiper sa2, therefore, advances in the contact group denoted by II and hunts in this group for the outgoing c-lead of an idle junction line over: earth, contacts 4402, 48s, 58t, 59a, switch wiper sa2, relay P2. Due to contact 6402 also being opened on the energization of relay C2, relay E2 was energized over: earth, contact 4502, windIng'II of relay.C2, relay E2, battery, earth. Relay E2 disposes its contact 5562 in position 7162 and thereby disconnects relays X and Y from the a-Zead. At the same time it switches through th a-lead.

In a manner similar to that described above,

' for example, for the setting up of a connection to the main exchange corresponding to a third 1 15 trafiic direction, alternating current impulses of the frequency f1+f2+f3 are transmitted over the junction line VL and influence relays J2,- X and Y so that in turn relaysS, 02, T and U areenergized and the group selector hunts in the line group denoted by III.

At the end of the conversation the switch pre ceding the group selector GWl cuts off the c-lead in known manner, thus causing relay C1 to release. Relay El consequently releases due to the opening of contact 701 and opens its contact 22e1. This causes relays P1 and R to relapse. Contact 371', therefore, is, restored to position 2' and contact 381' to position 141-. Due to the throwing over of the latter contact the circuit for relay F 1 is cut off and contact 74f is closed. There is now a circuit for relay J1 over: earth, contacts 75b1, 74f, winding II of relay J 1, battery, earth until relay G has been released due to the opening of I contact 72/ and, subsequently, relay H1 due to the opening of contact 739, whereupon the circuit for relay J1 is cut off at contact 75711. Relay J 1, therefore, closes its contacts 6871 and 6911 during a period corresponding to the total release periods of the three relaysG, H1, and J1 of a longer alterhating current impulse of the frequency 11- 'is transmitted in this manner over the junction line VL which influences relay J2 to such an extent that the short-circuit for relay 02 due to the clOs-r ing of contact 7672 over: earth, contacts 7672, 145 6602 and consequently cuts off the circuit extendingover the outgoing c-lead, thereby initiating the release of the succeeding connecting device also. Since the circuit for relay E2 has also been out 01f on the opening of contact 4502 this relay 35 is caused to release whereupon the arrangement is completely restored to normal.

If a connection is to be set up within the subexchange over the group selector GWl, the switch is set to a level to which, for example, the repeater Uel is connected. When such a connection is to be set up within the sub-exchange the switch wiper sal brushes the interconnected contact segments only. Relay Cl is energized on the seizure of the switch and consequently energizes relay Q over: earth contacts 1001, 130, relay Q, contact l lr, switch wiper 3, c-lead, contacts 15f, 1671.1, resistance, battery, earth. Relay Q closes contact 28g and, at the end of the impulse series which causes the switch wipers to be raised to a definite level, a circuit for relay 0 is closed on the release of relay V as follows: earth, battery, winding I of relay 0, switch wiper 861, contacts 261;, 5a, 27v, 2851, switch wiper I, a-lead, contacts 29 3012 I, primary winding of the speaking current repeater S191, contacts 3171, 32 b-lead, switch wiper 2, contact 331, earth. Relay Q is energized and maintained in this condition over contacts lOcl and 340. In addition it opens its contacts 350 and 360 causing the secondary lineswitch to be disconnected. When the c-wiper of the group selector encounters an idle repeater, relay P1 is energized in known manner. This relay closes its contact 23:01 which causes the group selector to be guarded against further seizures, and also actuates contacts 24101 and 25101 and thereby connects the switch to the repeater.

What is claimed is:

1. In a multi-oifice or multi-exchange automatic telephone system, a trunk line extending from a first ofiice or exchange to a second ofiice, an incoming directively operable switch in the second ofiice in which said trunk line terminates, an automatic switch in the first ofiice, means for directively operating said automatic switch for selecting a definite traflic direction, means responsive to the setting of said automatic switch for transmitting an alternating current signal over said trunk line specific to the selected traific direction, and means responsive thereto in the second ofiice for setting said incoming switch to the required traffic direction.

2. In a switching system, a local switch and an outgoing switch, lines accessible to said outgoing swltch, said local switch being responsive to a received series of impulses to set itself in a position depending upon the number of impulses in the series, means efiective upon the termination of the series of impulses for causing said outgoing switch to seize an idle one of the lines accessible thereto, and means thereupon effective and dependent upon the setting of said local switch for transmitting alternating current by way of a wiper of the local switch over the line taken into use by the outgoing switch.

3. In an automatic telephone system, a trunk line, an automatic switch, means for transmitting impulses corresponding to various digits to saidswitch, said switch responsive to the transmission of a digit of a desired number and independent of whether said digit has any particular one of a plurality of predetermined values for operating said switch to seize said trunk line, and means also responsive to said digit and depending upon the value of the digit for transmitting a signal of alternating current over said trunk line characteristic oi the value of said digit.

4. In a telephone system, a sub-exchange and a main exchange to which said sub-exchange is subsidiary, means responsive to an initiation of a call in the sub-exchange for taking a local switch for use, means responsive to the dialling of a digit indicating a number which may be reached by way of the main exchange for taking a main exchange trunk line for use'and for operating said local switch to an extent dependent upon the Value of the digit, and meanscontrolled in accordance with the position assumed by said local switch for transmitting a signal over the main exchange trunk line characteristic of the value of the digit used to operate the local switch.

5. In a telephone system as claimed in claim 4, a switch in the main exchange terminating said main exchange trunk line, and means responsive to said signal for forthwith positioning said main exchange switch in accordance with the digit value indicated by said signal.

6. In an automatic telephone system, a subexchange and a main exchange, a directively operable switch in the sub-exchange, local lines.

accessible to said switch, an automatic switch associated with said first switch, trunk lines accessible to said automatic switch leading to the main exchange and terminating therein in main exchange switches having access to a plurality of groups of lines, means for transmitting impulses corresponding to digits of called numbers to the directive switch in the sub-exchange, said automatic switch operated responsive to the first digit to select an idle one of said trunks, said directive switch having means for transmitting a selecting impulse over the selected trunk, after seizure, of a character dependent on the value of the digit transmitted to the directive switch, said main exchange switch responsive to said selecting impulse to elect a group of the lines accessible thereto.

MAXIMILIAN MATHIAS. 

